1. Field of the Invention
Aspects of the present invention relate to an optical disc drive, and, more particularly, to an optical disc drive that is capable of preventing shaking of a tray, thereby minimizing vibration and noise generated from the tray.
2. Description of the Related Art
Generally, an optical disc drive is an apparatus that irradiates light to a disc-shaped optical medium (hereinafter, referred to as a “disc”), such as a compact disc (CD), a digital versatile disc (DVD), or a blu-ray disc (BD), to record data to the disc or reproduce data from the disc.
FIG. 1 is a perspective view schematically illustrating a conventional optical disc drive, and FIG. 2 is a sectional view taken along line I-I of a part “A” of FIG. 1 when a tray is inserted in a main frame. As shown in FIG. 1, the conventional optical disc drive includes a main frame 1 and a tray 2, which may be disposed such that the tray 2 is inserted into or ejected from the main frame 1 while a disc is loaded on the tray 2. The tray 2 is slid into the main frame 1 or ejected from the main frame 1 by the cooperation of a loading motor and a pinion gear mounted at the front part of the main frame 1 and a rack gear mounted at the lower surface of the tray 2.
Guide rails 3 to guide the sliding movement of the tray 2 and protrusions 4 are provided at opposite sides of the main frame 1, as shown in FIGS. 1 and 2. The guide rails 3 protrude to a predetermined height from opposite side parts of the bottom surface of the main frame 1. The guide rails 3 are fitted in guide grooves 5 formed at the lower surface of the tray 2 to correspond in location to that of the guide rails 3 to prevent the tray from shaking from side to side when the tray 2 is slid. As shown in FIG. 1, a plurality of guide rails 3 may be arranged in the direction in which the tray 2 is slid.
The protrusions 4 horizontally protrude a predetermined length from the inner surfaces of the opposite sides of the main frame 1. As shown in FIG. 2, the protrusions 4 are positioned above the opposite side ends of the tray 2 to prevent the tray 2 from shaking up and down when the tray 2 is slid. Like the guide rails 3, a plurality of protrusions 4 may be also arranged in the direction in which the tray 2 is slid.
As is described above, the lateral and vertical shaking of the tray 2 is effectively prevented by the guide rails 3 and the protrusions 4. The conventional optical disc drive is designed such that predetermined gaps are provided between the guide rails 3 and the guide grooves 5 and between the protrusions 4 and the upper surface of the tray 2 to minimize friction generated when the tray 2 is slid.
When the disc is recorded/reproduced, however, noise is generated due to the gaps. When the disc is rotated, vibration is generated, and the vibration is transmitted to the tray 2. As a result, the tray 2 may shake up and down or from side to side, and therefore, the tray 2 may collide with the guide rails 3 or the protrusions 4. This problem is increased as high-speed recording/reproducing technology is advanced (for example, 52-X for CDs and 16-X for DVDs).
To solve the above-mentioned and/or other problems, an optical disc drive having additional holders to prevent shaking of the tray has been proposed. FIG. 3 illustrates such an optical disc drive. A plurality of holders 6 are mounted at a cover 7, which covers the top of the tray 2, to press the edge of the upper surface of the tray 2 when the disc is loaded/unloaded and when the disc is recorded/reproduced. To this end, each of the holders has a spring 6a and a pressing member 6b to press the edge of the upper surface of the tray 2 by the elastic force of the spring 6a. 
The holders 6 prevent shaking of the tray when the disc is recorded/reproduced. However, the holders press the tray 2 even when the tray is slid to load/unload the disc. As a result, friction between the components is increased when the tray 2 is slid, and therefore, a large load is applied to the loading motor.